I did a test, not long ago, for a hotel chain that was using such login screens and ssl. I used a combination of ARP spoofing / MITM (to catch the login credentials,) and then MAC spoofing and was able to gain access pretty quickly.

You simply need to take your time, and work out each piece of the puzzle, methodically, before you start hacking away, to make sure you have a good feel for how to get by each measure of security. SSL, when used with a webpage login, is extremely vulnerable to the MITM attacks, particularly where you're dealing with either hotel visitors or hotel staff (who generally are NOT well-versed in security, and who will readily click on SSL certificate messages, without thinking.

And, as Don says, however, you ARE doing this for legit purposes, correct?

~ hayabusa ~

"All men can see these tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved." - Sun Tzu, 'The Art of War'

This is one of those times when a windows tool can do the job nicely. Cain and Abel is a great tool for Mitm, arp poison routing and good ole network sniffing. I have found it does a great job testing the security for most hotel login screens.